1. Field of Invention
The present invention relates to a solid SCR system and a heating method for a solid SCR reductant. More particularly, the present invention relates to a solid SCR system and a heating method for a solid SCR reductant using the solid SCR system which uses waste heat exhausted through an exhaust pipe.
2. Description of Related Art
Generally, exhaust gas exhausted from an exhaust manifold of an engine is guided to a catalytic converter disposed and purified, and then passes though a muffler to reduce noise, and then finally is exhausted through an exhaust pipe to atmosphere.
The catalytic converter treats pollutant such as NOx within the exhaust gas.
A Selective Catalytic Reduction (SCR) apparatus, one of the catalytic converter, purifies NOx within the exhaust gas, and urea, ammonia, carbon monoxide and hydrocarbon (HC) and so on are used as reductant.
When the reductant is supplied to the exhaust gas, nitrogen oxide within the exhaust gas is deoxidized to nitrogen by oxidation-reduction reaction with the reductant.
The SCR, one of exhaust gas post processing devices, may remove nitrogen oxide regardless vehicle driving condition, and an urea SCR may reduce nitrogen dioxide and nitrogen monoxide within exhaust gas to nitrogen gas by dosing urea into the exhaust gas.
FIG. 5 is a partial cross-sectional view showing a conventional solid SCR system.
Referring to FIG. 5, solid state reductant 20 is stored within a container 10. When a pump 34 and a heat exchanger 32 are operated, a heat exchanging medium 30 applies heat to the solid state reductant 20 in order to be converted to gas state reductant 80.
And then the gas state reductant 80 controlled by a control valve 60 is supplied to an exhaust pipe 94 disposed in front of a SCR catalyst 90 via a supply pipe 70.
At this moment, signals of temperature and pressure within the container 10 are transmitted from a pressure/temperature signal transmitter 40 to a controller 50.
However, a conventional solid SCR system has complicated structure and cost of an entire system is relative high and thus practically it is not used widely.
The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.